Chemical Evolution of Seasonal Snowpack in the Ganga Headwater Region, Bhagirathi Valley, Garhwal Himalaya, India

The chemical characteristics of fresh snow and upper and lower parts of the snowpack have been used to understand the chemical evolution of seasonal snowpack at the Garhwal Himalaya. The chemistry of the meltwater leachates has also been used to determine the mechanism of removal of soluble ions from the melting snowpack. The snowpack chemistry results showed higher concentrations for most of the ions in the upper part of the snowpack than in the fresh snow, while the solute concentration decreases from upper to lower part of the snowpack. Snowpack chemistry is the integrate effect of dry and wet deposition, pack weathering, preferential elution, ground temperature and sample location on the slope. The chemical characteristics show preferential elution, and the relative order of preferential elution rate for the major ions were observed as NO₃⁻>SO₄⁻² >Cl⁻ and Ca⁺² >Mg⁺²>K⁺>Na⁺. Sodium and chloride are consistently found to have the least rate of preferential elution.